How evolution made our brains lazy

Blame our ancestors for why it's easier to be a couch potato.

Frog on couch
Pixabay.com
  • A new study shows that the brain prefers to expend as little energy as possible.
  • Putting forth less effort had advantages for our ancestors.
  • Being inactive is not beneficial in modern life and needs addressing.

Why is it often so hard to get off the couch and go to the gym? While you can certainly point to your lack of will power for the inaction, you can also blame evolution for this predicament. Your brain prefers to minimize effort because that's how it's been trained to do it for millennia.

Scientists from the University of Geneva (UNIGE) and the University Hospitals of Geneva (HUG) in Switzerland came to this conclusion after studying the neuron activity of people who had the choice of either engaging in physical activity or doing nothing. The researchers found that it takes much more effort for the brain to escape its general tendency to put forth less effort.

This battle in the mind comes courtesy of our ancestors who aimed to do less to increase the likelihood they would survive. Expending unnecessary energy would have made them more vulnerable to predators or environmental factors. Conserving energy was helpful when competing against rivals, fighting, hunting for prey, and searching for food. Living in modern societies does not require this approach, and yet the predilection of our brains to work less persists.

To gain a better understanding, the scientists based their hypothesis on "the physical activity paradox." You've experienced it if you've ever done something like buying a membership to a gym that you attend with less frequency each passing week. This happens when the conflict between your reason-based knowledge (going to the gym is good for my health) runs into the automatic system based on affect, which is, in this case, all the hurt and tiredness you expect to get out of the physical activity. The result is often paralysis—you remain sedentary.

To delve deeper into what is taking place at the neuronal level, the researchers studied the brain activity of 29 people who desired to be more active in their everyday lives but had a hard time doing so. The subjects were made to choose between physical activity or inactivity as the researchers observed their brains using an electroencephalograph (EEG) with 64 electrodes.

The research team was headed by Boris Cheval from the Faculty of Medicine at UNIGE and HUG and Matthieu Boisgontier from Leuven University, Belgium, and the University of British Columbia, Canada.

Cheval explained how the experiment, where subjects controlled an online avatar, was carried out:

We made participants play the "manikin task," which involved steering a dummy towards images representing a physical activity and subsequently moving it away from images portraying sedentary behaviour [...] They were then asked to perform the reverse action.

The scientists looked at how long it took the participants to get near the sedentary image versus avoiding it and found that it took the subjects 32 milliseconds less to move away from the less active image. Cheval called this result "considerable for a task like this." While such an outcome didn't correspond to their theory of the physical activity paradox at first glance, it actually ended up confirming it.

This animation shows the experiment the participants were asked to perform, moving the avatar closer or farther from the image shown.

Credit: UBC Media Relations

It turned out that the reason for why the participants moved their avatar away from images of physical inactivity and towards active pictures more quickly is because avoiding lazy images forced their brains to work harder. That's due to the fact that the participants wanted to engage in physical activity even if they weren't doing so. Choosing more active images was actually easier to do. As such, the EEG scans suggested that their brains were essentially hardwired towards laziness.

Matthieu Boisgontier explained why evolution preferred the easy way out:

Conserving energy has been essential for humans' survival, as it allowed us to be more efficient in searching for food and shelter, competing for sexual partners, and avoiding predators. [...] The failure of public policies to counteract the pandemic of physical inactivity may be due to brain processes that have been developed and reinforced across evolution.

He thinks one big takeaway from the study is that the brain has to work hard to avoid physical activity. The team's research will next focus on whether the brain can be re-trained.

Check out the new study, published in the journal Neuropsychologia, here.


A landslide is imminent and so is its tsunami

An open letter predicts that a massive wall of rock is about to plunge into Barry Arm Fjord in Alaska.

Image source: Christian Zimmerman/USGS/Big Think
Surprising Science
  • A remote area visited by tourists and cruises, and home to fishing villages, is about to be visited by a devastating tsunami.
  • A wall of rock exposed by a receding glacier is about crash into the waters below.
  • Glaciers hold such areas together — and when they're gone, bad stuff can be left behind.

The Barry Glacier gives its name to Alaska's Barry Arm Fjord, and a new open letter forecasts trouble ahead.

Thanks to global warming, the glacier has been retreating, so far removing two-thirds of its support for a steep mile-long slope, or scarp, containing perhaps 500 million cubic meters of material. (Think the Hoover Dam times several hundred.) The slope has been moving slowly since 1957, but scientists say it's become an avalanche waiting to happen, maybe within the next year, and likely within 20. When it does come crashing down into the fjord, it could set in motion a frightening tsunami overwhelming the fjord's normally peaceful waters .

"It could happen anytime, but the risk just goes way up as this glacier recedes," says hydrologist Anna Liljedahl of Woods Hole, one of the signatories to the letter.

The Barry Arm Fjord

Camping on the fjord's Black Sand Beach

Image source: Matt Zimmerman

The Barry Arm Fjord is a stretch of water between the Harriman Fjord and the Port Wills Fjord, located at the northwest corner of the well-known Prince William Sound. It's a beautiful area, home to a few hundred people supporting the local fishing industry, and it's also a popular destination for tourists — its Black Sand Beach is one of Alaska's most scenic — and cruise ships.

Not Alaska’s first watery rodeo, but likely the biggest

Image source: whrc.org

There have been at least two similar events in the state's recent history, though not on such a massive scale. On July 9, 1958, an earthquake nearby caused 40 million cubic yards of rock to suddenly slide 2,000 feet down into Lituya Bay, producing a tsunami whose peak waves reportedly reached 1,720 feet in height. By the time the wall of water reached the mouth of the bay, it was still 75 feet high. At Taan Fjord in 2015, a landslide caused a tsunami that crested at 600 feet. Both of these events thankfully occurred in sparsely populated areas, so few fatalities occurred.

The Barry Arm event will be larger than either of these by far.

"This is an enormous slope — the mass that could fail weighs over a billion tonnes," said geologist Dave Petley, speaking to Earther. "The internal structure of that rock mass, which will determine whether it collapses, is very complex. At the moment we don't know enough about it to be able to forecast its future behavior."

Outside of Alaska, on the west coast of Greenland, a landslide-produced tsunami towered 300 feet high, obliterating a fishing village in its path.

What the letter predicts for Barry Arm Fjord

Moving slowly at first...

Image source: whrc.org

"The effects would be especially severe near where the landslide enters the water at the head of Barry Arm. Additionally, areas of shallow water, or low-lying land near the shore, would be in danger even further from the source. A minor failure may not produce significant impacts beyond the inner parts of the fiord, while a complete failure could be destructive throughout Barry Arm, Harriman Fiord, and parts of Port Wells. Our initial results show complex impacts further from the landslide than Barry Arm, with over 30 foot waves in some distant bays, including Whittier."

The discovery of the impeding landslide began with an observation by the sister of geologist Hig Higman of Ground Truth, an organization in Seldovia, Alaska. Artist Valisa Higman was vacationing in the area and sent her brother some photos of worrying fractures she noticed in the slope, taken while she was on a boat cruising the fjord.

Higman confirmed his sister's hunch via available satellite imagery and, digging deeper, found that between 2009 and 2015 the slope had moved 600 feet downhill, leaving a prominent scar.

Ohio State's Chunli Dai unearthed a connection between the movement and the receding of the Barry Glacier. Comparison of the Barry Arm slope with other similar areas, combined with computer modeling of the possible resulting tsunamis, led to the publication of the group's letter.

While the full group of signatories from 14 organizations and institutions has only been working on the situation for a month, the implications were immediately clear. The signers include experts from Ohio State University, the University of Southern California, and the Anchorage and Fairbanks campuses of the University of Alaska.

Once informed of the open letter's contents, the Alaska's Department of Natural Resources immediately released a warning that "an increasingly likely landslide could generate a wave with devastating effects on fishermen and recreationalists."

How do you prepare for something like this?

Image source: whrc.org

The obvious question is what can be done to prepare for the landslide and tsunami? For one thing, there's more to understand about the upcoming event, and the researchers lay out their plan in the letter:

"To inform and refine hazard mitigation efforts, we would like to pursue several lines of investigation: Detect changes in the slope that might forewarn of a landslide, better understand what could trigger a landslide, and refine tsunami model projections. By mapping the landslide and nearby terrain, both above and below sea level, we can more accurately determine the basic physical dimensions of the landslide. This can be paired with GPS and seismic measurements made over time to see how the slope responds to changes in the glacier and to events like rainstorms and earthquakes. Field and satellite data can support near-real time hazard monitoring, while computer models of landslide and tsunami scenarios can help identify specific places that are most at risk."

In the letter, the authors reached out to those living in and visiting the area, asking, "What specific questions are most important to you?" and "What could be done to reduce the danger to people who want to visit or work in Barry Arm?" They also invited locals to let them know about any changes, including even small rock-falls and landslides.

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